In consideration of the maintenance of the health and well-being of chain saw operators, and in an effort to reduce chain saw operator fatigue levels, substantial efforts have been made in the chain saw art to develop vibration isolation systems.
In recent years, substantial advances in the art have been made in relation to a variety of vibration isolation systems.
For example, a number of uniquely effective vibration isolation systems have been developed by the assignee of the present invention, as evidenced by the following U.S. Patents:
Frederickson et al. No. 3,542,095 (Nov. 24, 1970) PA1 Frederickson et al. No. 3,652,074 (Mar. 28, 1972) PA1 Frederickson et al. No. 3,698,455 (Oct. 17, 1972) PA1 Frederickson et al. No. 3,813,776 (June 4, 1974) PA1 Bailey No. 3,845,557 (Nov. 5, 1974) PA1 Bailey No. 3,911,580 (Oct. 14, 1975) PA1 Bailey No. 3,972,119 (Aug. 3, 1976) PA1 Thompson No. 4,041,606 (Aug. 16, 1977) PA1 La Force No. 3,140,746 (July 14, 1964) PA1 Dobbertin et al. No. 3,224,473 (Dec. 21, 1965) PA1 Irgens No. 3,372,718 (Mar. 12, 1968) PA1 Rauh No. 3,409,056 (Nov. 5, 1968) PA1 Kobayashi No. 3,525,373 (Aug. 25, 1970) PA1 Scharpf No. 3,530,909 (Sept. 29, 1970) PA1 Sherwood, Jr. et al. No. 3,637,029 (Jan. 25, 1972) PA1 Stihl et al. No. 3,651,839 (Mar. 18, 1972) PA1 Emmerich et al. No. 3,680,608 (Aug. 1, 1972) PA1 Kobayashi et al. No. 3,700,015 (Oct. 24, 1972) PA1 Makinson et al. No. 3,728,793 (Apr. 24, 1973) PA1 Notaras et al. No. 3,733,700 (May 22, 1973) PA1 Heermann No. 3,772,784 (Nov. 20, 1973) PA1 Schulin No. 3,845,827 (Nov. 5, 1974) PA1 Kolorz No. 3,849,883 (Nov. 26, 1974) PA1 Dillon No. 3,889,763 (June 17, 1975) PA1 Nagashima et al. No. 3,945,119 (Mar. 23, 1976) PA1 a vibration generating assembly including PA1 a handle assembly including PA1 vibration isolating means interconnecting the handle means and the vibration generating assembly. PA1 first and second vibration isolating assemblies mutually spaced longitudinally of the chain saw and cooperating with the handle assembly to define a resilient suspension for the vibration generating assembly, disposed generally on the aforesaid one side portion of the chain saw; and PA1 force transmitting, cross-over linkage means connected with the resilient suspension and operable to transmit forces acting on the resilient suspension generally transversely of a longitudinal median plane of the chain saw, passing generally through the center of gravity thereof, to an opposite side portion of the chain saw. PA1 a structural foam handle including PA1 a rigid, closed cell, cellular resin core, PA1 fibrous elements reinforcing the resin core, and PA1 a solid resin skin substantially surrounding the cellular resin core. PA1 the front handle and rear handle define an interconnected handle assembly comprising structural foam handle means including PA1 the first and second vibration isolating assemblies are generally aligned with a longitudinal plane generally coincident with the guide bar means; PA1 the chain saw includes base plate means underlying the engine means and spaced beneath the rear handle when the chain saw is in the upright cutting position; and PA1 the rear handle is disconnected from the base plate. PA1 a relatively rigid, force-transmitting tubular member, PA1 first, resilient, vibration absorbing, grommet means interconnecting one end of the tubular member with the aforesaid side portion of the rear handle means, and PA1 second resilient, shock absorbing grommet means interconnecting another end of the tubular member with the vibration generating assembly. PA1 the vibration generating assembly includes PA1 the first vibration isolating assembly includes PA1 apertured web means connected with the engine means, and PA1 resilient, elastomeric disk means, carried on shaft means projecting from an end of the aforesaid lower portion of the front handle, and sandwiched on opposite sides of this web means. PA1 a resilient, elastomeric cylinder means, PA1 an apertured web means carried by the vibration generating assembly mounted above the engine means and telescopingly receiving the cylinder means, PA1 an arrangement wherein the cylinder means is mounted on shaft means projecting from the above noted side portion of the rear handle, and PA1 cup means engaging opposite end of the resilient elastomeric cylinder means and axially compressing this resilient, elastomeric cylinder means.
Other activity in the chain saw vibration isolation art is evidenced by the following U.S. Patents:
The foregoing tabulations are presented by way of example and are not intended to constitute a complete compilation of all prior art disclosures dealing with vibration isolation systems. Nevertheless, it is believed that the tabulated patents do reasonably adequately depict the overall state of the art and the continuing efforts to develop improved and more effective vibration isolation systems for chain saw structures.
In furthering and advancing the chain saw vibration isolation art, the present applicants have developed a chain saw vibration isolation system which has been found to produce vibration acceleration rates as low as 2G in magnitude. Those skilled in this art will recognize the efficacy and uniqueness of such a low vibration acceleration rate in the context of a chain saw structure.
In accomplishing what is believed to be a significant advance in the chain saw vibration isolation art, through the present invention, a variety of individually significant aspects of the invention are herein presented.
In now summarizing these independently significant aspects of the invention, it will be recognized that these aspects should be considered to be significant in their own independent right, and particularly significant in a combination context.
Independently significant facets of the invention are presented as follows:
One such individually significant aspect of the invention pertains to a chain saw comprising
engine means, PA2 guide bar means extending generally longitudinally from one side portion of the chain saw, PA2 cutter chain means mounted on the periphery of the guide bar means for movement thereabout, and PA2 drive means operable to drivingly couple the engine means to the cutter chain means; PA2 a front handle, and PA2 a rear handle; and PA2 generally rigid, closed cell, cellular resin core means, PA2 fibrous elements reinforcing the cellular resin core means, and PA2 solid resin skin means substantially surrounding the cellular resin core means. PA2 a carburator receiving, air box mounted on the engine means, and PA2 web means connected with the air box, spaced from the engine means, and supporting the second, resilient, shock absorbing grommet means. PA2 a resilient, elastomeric shock absorbing connection between a lower portion of the front handle and a portion of the vibration generating assembly connected with a lower portion of the engine means;
In this context, the improvement afforded through this independently significant aspect of the invention resides in vibration isolating means comprising:
The aforesaid force transmitting, cross-over linkage means extends generally across the top of the engine means when the chain saw is in an upright cutting position.
Further, this force transmitting, cross-over linkage means is disposed generally longitudinally between planes which extend transversely of the aforesaid longitudinal median plane and are generally aligned with the first and second vibration isolating assemblies.
In addition, the force transmitting, cross-over linkage means cooperates with an upper portion of the front handle means and a side portion of the rear handle means to define a generally U-shaped, at least partially flexible, force transmitting, cantilever connection between the hand of a chain saw operator, engaged with the front handle, and an upper portion of the engine means when the chain saw is in the upright cutting position.
Another independently significant aspect of the invention involves a chain saw handle means comprising:
This structural foam handle is energy absorbing and resilient, shock absorbing coupling means are operable to connect the structural foam handle with a chain saw.
In addition to the aforegoing independently significant aspects of the invention, it is believed that the significance of the invention extends to additional features which are employed individually or in combination in the context of either or both of the foregoing individual invention aspects.
Such combination features of the invention are as follows.
One such combination feature involves a chain saw as heretofore described wherein:
In this combination feature, the structural foam handle means is energy absorbing and is resiliently interconnected with the vibration generating assembly through resilient shock absorbing coupling means comprising the aforesaid first and second vibration isolating assemblies.
Another such combination feature involves a chain saw as heretofore described wherein:
A third combination feature, in the setting of a chain saw as earlier noted, involves an arrangement wherein the force transmitting, cross-over linkage means includes
In addition, another combination feature relates to a chain saw as noted earlier and the force transmitting, cross-over linkage means described immediately above wherein:
Finally, this invention further contemplates a fifth combination feature, included with the chain saw described earlier wherein:
This particular first vibration isolating assembly may include:
This shaft means passes through an aperture of the above noted web means, and is operable to abuttingly engage this web means and provide a solid, force transmitting connection between the front handle and the vibration generating assembly.
In addition, in this fourth combination feature of the invention, the second vibration isolating assembly includes:
As earlier noted, the combination features above noted may be employed individually in the context of the chain saw and/or handle means noted at the outset of this summary of the invention discussion or may be employed in association with each other in this same context.
Having described and summarized basic aspects of the invention, it now becomes appropriate to give consideration to a particular, presently preferred embodiment which is illustrated in the accompanying drawings.